Although goldfish have always been a popular option for aquariums and ponds, more and more people are starting to include an algae eater with their goldfish to try and keep the algae under control.
Due to this, we have seen a spike in the number of people who are reaching out and asking if plecos can live with goldfish or not recently as they look to add a pleco to their aquarium or pond containing goldfish.
Plecos can live with goldfish in some very specific conditions but due to the cross over in recommended water temperatures between the two only having a very small suitable window, checkout our article on the best cold water algae eaters is probably a better option.
For the rest of this article, we are going to presume that you are able to get the water parameters and water temperature ideal for both your goldfish and pleco but please note that this is more difficult that most people think so is not usually recommended for beginners to fish keeping.
As we have noticed a number of slightly different questions about keeping plecos with goldfish, we have decided to compile them all in this article to try and provide as much information as possible to our readers.
The table of contents below should make it as quick and easy as possible for you to navigate the article to get to the specific information that you need though.
Can Plecos Live With Goldfish?
Plecos can live with goldfish in some very specific conditions with the main two being that the water has to consistently be between 72-74°F and the pond or tank that the goldfish and pleco are kept in should be at least double the recommended size for the number of fish in it.
Provided you can match both of these requirements, your goldfish and pleco would live together without issue.
The temperature requirement for the water is pretty straight forward but we often see people asking why we recommend that you double the recommended size of all fish in the body of water.
This is to ensure that there is plenty of space available for your goldfish and pleco to live happily to reduce the chances of your pleco developing a taste for the natural slime goldfish excrete onto their scales.
We always recommend that you follow the rule of thumb of one inch of fish per gallon of water. This allows you to workout the maximum adult sizes for the species of goldfish and the species of pleco that you have as different species will grow to very different sizes and then double it.
Will Plecos Eat Goldfish Food?
Most pleco species will happily eat any goldfish food that falls to the bottom of your aquarium or pond be it flake or pellet food.
If your pleco is eating goldfish flakes that fall to the bottom of the tank then keep in mind that its poop may change color due to not being able to process the dye in the flakes but this is normal for smaller plecos.
The majority of pleco species will eat almost anything that they find at the bottom of your tank ranging from algae and detritus to discarded fish food from your goldfish or other tank mates too.
Some plecos can have issues with eating in highly stocked tanks or ponds though so our article on why your pleco is not eating may help you with this.
For the most part though, provided your aquarium or pond is large enough for your pleco to feel comfortable it should eat without issue and it will eat plenty of discarded goldfish food.
Just keep in mind that plecos are usually nocturnal so they are most active while we sleep so just because you don’t see your pleco eating goldfish food does not mean that it is not.
Are Plecos Aggressive Towards Goldfish?
Provided your tank is large enough for your pleco and your goldfish then there should be no problems with aggression between your fish. The majority of reports of a pleco attacking goldfish is due to the tank or pond the fish are in being way too small for them.
If you are worried about aggression between you pleco and your goldfish then we would recommend that you go with a rubber lip pleco.
They are very passive and will not act aggressively towards any of their tank mates with the rubber lip pleco having an excellent reputation for being calm and peaceful.
In addition to the peaceful nature of a rubber lip pleco, they usually only grow to a maximum length of around seven inches making them a much better option for smaller aquariums.
Please note though, even though they are very peaceful to other fish, just like all other plecos, rubber lip plecos will instinctively presum that snails and shrimp in their tank are food and eat them.
Why Do Plecos Attach Themselves To The Sides Of Goldfish?
Some species of pleco will start to attach themselves to the sides of your goldfish to eat the biofilm slime that goldfish naturally secreate to protect their scales.
This is more common in smaller, heavily stocks tanks and is the main reason that we recommend that you at least double the recommended size for your stocking plans if you want to keep goldfish and plecos together.
Provided there is plenty of space in the aquarium or pond your pleco will usually not build up a taste for goldfish slime and leave you goldfish alone.
Although this behavior is not aggression, it can accidentally cause problems with your goldfish by damaging their scales and removing the bio slime that they use to protect their scales.
If you do notice your pleco is mounting your goldfish then we would recommend that you try to rehome your pleco in another tank or pond if possible. Once the pleco is used to mounting the goldfish to eat their bio slime it can be difficult to get your pleco to stop doing it.
Can Plecos And Goldfish Live In The Same Water Temperatures?
There is a very small cross over between the recommended water temperature for most pleco species of 72-82°F and most goldfish species of 68-74°F with the temperature cross over being 72-74°F.
Provided you are able to consistently maintain this water temperature then your goldfish and pleco should be fine.
Different plecos do have different temperature requirements and they can sometimes work well in lower temperatures in specific situations.
Our article on if plecos can live in cold water may be worth checking out as it goes into more detail on the temperature tolerance of plecos as goldfish do usually need lower water temperatures.
That said though, we usually recommend that you do keep your pleco above 72°F if possible, especially if you are looking at adding the pleco to your tank for its algae eating capabilities. The colder the water, the less the pleco will move and the less energy it will use meaning the less algae it will eat.
That brings our article going over if plecos can live with goldfish or not to an end. We hope that we have been able to help you better understand how you are able to safely integrate a pleco to your goldfish aquarium or pond as well as highlight some of the common mistakes that we make people make so you are able to avoid them. For the most part though, provided your tank is large enough and you are able to maintain the correct water temperature, your goldfish and pleco should be fine together.